Robert Mayer (second on the left) with his parents, the pharmacist Christian Jakob Mayer and Katharina Elisabeth, born Heermann, and his brother Carl Gustav

Robert Mayer (1814 - 1878): the contemporary of Adolf Cluss discovered the law of energy conservation

Robert Mayer discovers the Law of Energy Conservation

With the discovery by Robert Mayer (1814 - 1878) of the law of energy conservation, Heilbronn made an important contribution to the history of physics. The practical application of Mayer's truth accounted for the rapid technological development in the 19th century.

The son of a pharmacist came to his ingenious discovery indirectly. After his medical studies, the young physician signed on to work aboard a Dutch
ship in 1840. During a blood-letting in an East-Indian harbor, he recognized that the venous blood of the Europeans was pale red and looked like the
oxygenated arterial blood. Other doctors had noticed that phenomenon, but it remained unexplained. The answer came to Mayer like a thunderbolt. He concluded that the human body needs less oxygen in tropical climes than in temperate zones to maintain its blood heat. From this, he drew the conclusion that
motion and heat are "different manifestations of one and the same energy". So, they "must permute and transform into one another".

After his return to Heilbronn in 1841, Mayer devoted himself to showcasing his observations and conclusions to the scientific experts. But his first publication in 1842, "Notes on the powers of an inanimated nature", in which he calculated the quantitative relation between motion and heat, remained,
like his other essays, mostly unappreciated.

Though Robert Mayer, as a physician, did not belong to the scientific establishment, the "energy" issue was in the air and of interest to many physicists. It hurt Mayer deeply, when other researchers (Joule, Helmholtz) published the same topics later without mentioning him or crediting him with the first publication of the discovery.

After lenghty arguments, which precipitated Mayer's physical and psychological crisis, he earned long overdue recognition. His competitor, Helmholtz, admitted to the public in 1854 , that Mayer was entitled to credit for being the first to discover the law of energy conservation. Four years later, Justus Liebig charcterized him as the "father of one of the most important inventions in this century".

Robert Mayer died in March 1878, a highly honored scientist, the "German Newton", having made peace with himself and science. Today, he is still considered Heilbronn's greatest native son.